Transmission for slot racers



A ril 16, 1968 P. SHELDON ETAL 3,377,742

TRANSMISSION FOR SLOT RACERS 7 Filed Feb. '14. 1966 lllllllllllllll lnvmvroas PHILIP SHELDONI BY THOMAS J. BACSANYI WNVMW/ ATTORNEYS UnitedStates Patent 3,377,742 TRANSMISSION FOR SLOT RACERS Philip Sheldon,Rochester, and Thomas J. Bacsanyi,

Livonia, Mich., assignors to Model Products Corporation, Mount Clemens,Mich., a corporation of Michigan Filed Feb. 14, 1966, Ser. No. 527,332

6 Claims. (Cl. 46-243) This invention relates to a new and improveddrive train for a toy slot type racing car and has particular referenceto an automatic two speed transmission for use in a slot racer.

In conventional slot type racing cars the electric drive motor is geareddirectly to the drive axle. The gear ratio is usually selected as acompromise between a gear ratio which would allow the racer to attainhigh track speeds, and one which would provide rapid starting andacceleration of the racer. The invention provides a reliable yetinexpensive two speed transmission for a slot type racing car whichincludes a low speed drive having a relatively high gear ratio to permitrapid starting and acceleration of the racer and a high speed drivehaving a low gear ratio for high track speed operation. The transmissionshifts automatically from the low speed drive to the high speed driveand back again in order to assure maximum performance as the racer isdriven around the race track.

An object of the invention is to provide an improved transmission for atoy racing car.

Another object of the invention is to provide an automatic two speedtransmission for a slot racer.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings illustrating a preferred embodiment of theinvention, wherein:

FIGURE 1 is a top view of a slot racer according to the invention withpart of the chassis broken away;

FIGURE 2 is an enlarged view showing the drive train with the automatictransmission in the low speed position;

FIGURE 3 is like FIGURE 2 but shows the transmission in the high speedposition;

FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 2; and

FIGURE 5 is a sectional view taken along line 5-5 of FIGURE 4.

A toy racing car according to the invention includes an elongatedchassis having a front axle 12 journaled in front bearings 14 carried bythe chassis. Front wheels 16 are secured on the ends of the front axle12. Rear drive wheels 18 are secured to a rear axle 20 rotatably mountedon the chassis 10. The wheels 16 and 18 support the racer on aconventional slot type track 22 over a guide slot 24 having electrifiedpower rails 26 at either side thereof. A conventional contact and guidemember 28 is mounted in the front of the chassis 10. Electric drivemotor 30 is secured to the chassis adjacent the rear axle 20 with thedrive shaft thereof oriented parallel to the rear axle. Lead-in wires 32are secured to the contacts carried by contact member 28 and supplyelectric power to the motor 30 from the rails 26.

Motor drive shaft 34 is journaled in bearings 36 carried by chassis 10and extends outwardly to each side thereof. Low speed gear 38 and highspeed gear 40 are secured to the ends of the drive shaft 34 outside ofthe chassis 10. Low speed gear 42 is journaled in a bearing 44 carriedon one side of the chassis 10 and high speed gear 46 is journaled in abearing 48 carried by the chassis opposite bearing 44. The drive axle 20is journaled in axial bores 50 and 52 in the low speed and high speedgears 42 and 46, respectively. The gears 42 and 46 are provided withhubs 53 which are journaled in bearings 44 and 48 and 'ice have endfaces provided with a plurality of pin engaging slots 54. Gear 38engages low gear 42 and gear 40 engages gear 46 so that the motor 30rotates the gears 42 and 46 at all times. The gear ratios are such thatthe gear 42 is rotated at a lower speed than the gear 46.

Collar 56 is secured to the drive axle 20 adjacent gear 46 by set screw58. A collar 60 is slidably mounted on axle 20 adjacent gear 42. Controllinks 62 and 64 connect the collars 56 and 60 by means of pivot jointswhich allow the links to move radially outwardly from the slow speedposition as shown in FIGURE 2 to the high speed position shown in FIGURE3. Links 62 carry weights 66 adjacent their connection with links 64.Shift pin 68 is secured to the free collar 60 by a set screw andprojects toward the low speed gear 42 so as to engage one of the slots54 in the hub 53 thereof when the collar 60 is in the low speed positionshown in FIGURES 2, 4 and S. Shift pin 70 is also secured to the collar60 by a set screw and extends toward the slots 54 in the: hub 53 of highspeed gear 46. Pin 70 has a sliding fit in bore 73 of fixed collar 56 sothat collar 60 rotates with axle 20 and collar 56. Spring 74 is confinedbetween collars 56 and 60 on pin 70 and serves to bias the collar 60toward the low speed position of FIGURE 4.

When the racer is started the collar 60) is held adjacent the low speedgear 42 by spring 74 and pin 68 engages one of the slots 54 in low speedgear 42 so that the axle 20 and rear wheels 18 are driven at the samerotational speed as the gear 42. High speed gear 46 is then rotatedfreely on the axle 20 by the motor 30. As the racer accelerates, therotating weights 66 are thrown radially outwardly of the drive axle 20and links 62 and 64 draw the collar 60 against the action of the spring74 toward fixed collar 56 until the high speed position illustrated inFIG- URE 3 is reached wherein pin 68 has been moved out of engagementwith the slot 54 in the hub of low speed gear 42 and pin 70 has beenmoved through bore 72 and into engagement with one of the slots 54 inthe hub of high speed gear 46. The gear 42 is now rotating freelyrelative to axle 20 which is driven through the high speed gears 40 and46.

When the racer is slowed, the centrifugal force exerted by weights 66 isreduced and the spring 74 moves the collar 60 away from fixed collar 56,and the pin 70 disengages gear 46 while pin 68 engages gear 42 at theappropriate shift speed so that the motor 30 drives the axle 20 throughthe low speed gear train. The shift pins 68 and 70 are adjusted relativeto collar 60 so that the shift from the low speed to high speed gearsand back again occurs smoothly without locking the wheels.

It will be apparent that the pin 68 could be eliminated and the pin 70extended outwardly from the collar 60 into engagement with one of theslots 54 in the hub of the low speed gear 42 if desired, so that asingle pin would perform the function of the two pins shown in theillustrated embodiment of the invention.

While we have illustrated and described a preferred embodiment of ourinvention, it is understood that this is capable of modification, and wetherefore do not wish to be limited to the precise details set forth,but desire to avail ourselves of such changes and alterations as fallwithin the purview of the following claims.

What we claim as our invention is:

1. A slot type racer having a two-speed automatic transmissioncomprising a chassis, an axle rotatably supported by said chasssis, adrive wheel mounted on said axle and engageable with a track so as todrive the racer therealong, low and high speed gears journaled on saidaxle, an electric drive motor carried by said chassis, drive meansoperatively connecting said motor to said gears so that the motorcontinuously rotates such gears, and automatic shift means carried bysaid axle and operable responsive to centrifugal force to connect saidlow speed gear to said axle at low axle speeds and to connect said highspeed gear to said axle at high axle speeds.

2. A toy racer as in claim 1, wherein said automatic shift meanscomprises a fixed collar on said axle, a free collar slidably mounted onsaid axle, a pair of links connecting said collars with one end of eachlink pivotally secured to one of said collars and the other ends thereofpivotally joined to allow radial movement of the links relative to theaxle, spring means urging said collars apart, gear shift means carriedby said free collar and extending therefrom toward each of said axlegears, said gears each having means thereon engageable by said gearshift means, said gear shift means being arranged so that at low axlespeeds said spring holds said collars apart to engage said gear shiftmeans with said low speed gear so that the motor rotates the axlethrough said low speed gear and fixed collar, and at high axle speedssaid links are thrown radially away from said axle "by centrifugal forceto move said free collar toward said fixed collar against the force ofsaid spring means to disengage said gear shift means from said low speedgear and engage said gear shift means with said high speed gear so thatthe motor then drives the axle through said high speed gear and saidfixed collar.

3. A racer as in claim 2 wherein said gears are journaled in bearingscarried by said chassis and secure said axle relative thereto.

4. A racer as in claim 2 wherein said drive motor is positioned adjacentsaid axle with the drive shaft oriented parallel thereto, and said drivemeans comprises gears mounted on the opposite ends of said drive shaftand engaged with said high and low speed gears.

5. A racer as in claim 2 wherein said gear change means includes a pinsecured to said free collar and extending slidably through an opening insaid fixed collar.

6. A racer as in claim 4 including a drive wheel on each end of saidaxle and wherein said low and high speed gears are spaced apart and eachdisposed adjacent one of said wheels, said automatic shift means beingmounted on said axle between said gears.

References Cited UNITED STATES PATENTS 12/1964 Ziroli 46243 X 1/1966Thompson 180-75

1. A SLOT TYPE RACER HAVING A TWO-SPEED AUTOMATIC TRANSMISSIONCOMPRISING A CHASSIS, AN AXLE ROTATABLY SUPPORTED BY SAID CHASSIS, ADRIVE WHEEL MOUNTED ON SAID AXLE AND ENGAGEABLE WITH A TRACK SO AS TODRIVE THE RACER THEREALONG, LOW AND HIGH SPEED GEARS JOURNALED ON SAIDAXLE, AN ELECTRIC DRIVE MOTOR CARRIED BY SAID CHASSIS, DRIVE MEANSOPERATIVELY CONNECTING SAID MOTOR TO SAID GEARS SO THAT THE MOTORCONTINUOUSLY ROTATES SUCH GEARS, AND AUTOMATIC SHIFT MEANS CARRIED BYSAID AXLE AND OPERABLE RE-